rust/tests/ui/variance/variance-unused-type-param.rs

29 lines
686 B
Rust

#![allow(dead_code)]
// Test that we report an error for unused type parameters in types and traits,
// and that we offer a helpful suggestion.
struct SomeStruct<A> { x: u32 }
//~^ ERROR parameter `A` is never used
enum SomeEnum<A> { Nothing }
//~^ ERROR parameter `A` is never used
// Here T might *appear* used, but in fact it isn't.
enum ListCell<T> {
//~^ ERROR parameter `T` is never used
Cons(Box<ListCell<T>>),
Nil
}
struct WithBounds<T: Sized> {}
//~^ ERROR parameter `T` is never used
struct WithWhereBounds<T> where T: Sized {}
//~^ ERROR parameter `T` is never used
struct WithOutlivesBounds<T: 'static> {}
//~^ ERROR parameter `T` is never used
fn main() {}